...
<theme extends="Bootstrap3_blank" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="platform:/plugin/com.ibm.designer.domino.stylekits/schema/stylekit.xsd" >
<resources>
<styleSheet href="/bootstrap.min.css"></styleSheet>
<script src="/bootstrap.min.js" clientSide="true"></script>
<styleSheet href="/.ibmxspres/.extlib/responsive/dijit/dbootstrap-0.1.1/theme/dbootstrap/dbootstrap.css"></styleSheet>
<styleSheet href="/.ibmxspres/.extlib/responsive/xpages/css/xsp-mixin.css"></styleSheet>
</resources>
<control>
<name>ViewRoot</name>
<property mode="concat">
<name>styleClass</name>
<value>xsp dbootstrap</value>
</property>
</control>
</theme>
...